The classic folk toy gets easier.
Here is a paradox: Tops are ancient. Clay tops have been found in archeological digs dating back over 5000 years. The Iliad, by the ancient Greek Homer, contains a reference to tops. So does The Republic, by fellow Greek, Plato. More "recently", Shakespeare referred to tops many times in his works.
Yet, tops are so cutting edge. The key to the balancing Segway scooter is the gyroscope. A gyroscope is a top with a frame and a motor to keep it going. Gyroscopes make aviation guidance systems like auto-pilot work. Finally, the physics of tops remain a mystery even to most people who understand most other basic physics concepts. Precession--the scientific term for the force that keeps the top up-- is one the most counterintuitive concepts in science.